Figure 5. Alveolar fluid clearance and Na⁺,K⁺-ATPase activity in electroporated rat lungs.

A. Alveolar fluid clearance was measured in isolated lungs, three days after the indicated non-viral treatment or 10 days after recombinant adenoviral infection. Plasmids were administered at 600 μg per animal and electroporations were carried out at 200 V/cm using 8 pulses of 10 μsec each. Ad-β1 was administered in surfactant at 5 × 10⁸ pfu per animal. Alveolar fluid clearance was measured as described in Methods (mean ± sem, n=6). *, p < 0.003 versus all conditions except Ad-β1 and pCMV-β1 + electroporation, using the non-parametric Mann-Whitney U test. B. Na⁺,K⁺-ATPase activity in ATII cells isolated from treated lungs, three days post-treatment. Plasmids (600 μg) were transferred to rat lungs with or without electroporation (200 V/cm, 8 pulses at 10 μsec each). Ouabain-sensitive ⁸⁶Rb+ uptake was measured (mean ± sd, n=3) as an indicator of Na+,K+-ATPase activity. *, p < 0.005 versus all other conditions using the non-parametric Mann-Whitney U test. C. Western blot of β1 protein abundance in basolateral membranes of naïve rats and those electroporated with pCMV-β1 as in B (n=5).